As it braces for the likelihood of a new ruler in Egypt, the U.S. government is rapidly reassessing its tenuous relationship with the Muslim Brotherhood, an opposition movement whose fundamentalist ideology has long been a source of distrust in Washington.

Although the group has played a secondary role in the swelling protests that are threatening to topple President Hosni Mubarak, U.S. officials have acknowledged the political reality that the Muslim Brotherhood is poised to assume at least a share of power should Egypt hold free and fair elections in the coming months.

On Monday, in what analysts said was a clear reference to the Brotherhood, the White House said a new government in Egypt should "include a whole host of important non-secular actors."

The move drew the skepticism of some U.S. officials who have argued that the White House should embrace opposition groups that are more likely to support a democratic government in Egypt, rather than one dedicated to the establishment of religious law.

It also marked a change from previous days, when Secretary of State Hillary Rodham Clinton and other officials expressed concern that the uprising in Egypt could shift power to an Islamist government much like the one in Iran, where ayatollah-led factions elbowed aside other groups to seize control of the country in 1979.

Officially, the U.S. government has long shunned the Muslim Brotherhood because of doubts about its stated commitment to non-violence and democratic principles. For years, however, U.S. officials have engaged in back-channel talks with Egyptian members of the movement in recognition of its substantial popular support.

The unofficial contacts have taken place sporadically since the 1990s but became more frequent after members of the Brotherhood were elected to the Egyptian Parliament in 2005. Afterward, U.S. diplomats and lawmakers held several meetings with Brotherhood leaders, including at the U.S. Embassy in Cairo.

U.S. officials justified the meetings by saying they were merely speaking with duly-elected members of the Egyptian legislature.

"I do think that having contacts with the Muslim Brotherhood was not a bad idea," said Robert Malley, an official in the Bill Clinton administration who directs the Middle East and North Africa program for the International Crisis Group. "They are an important constituency in Egypt. They're very likely to play a role in any future arrangements there."

Some U.S. officials and analysts have long urged the State Department to reach out even further to the Brotherhood.

"If we are truly going to engage with the 99 percent of Muslims who do not support terrorism or violence, then we've got to engage indigenous groups, including Islamic political parties," said Emile Nakhleh, a former CIA official who directed the agency's political Islam analysis program.

Although the Brotherhood is Egypt's best organized opposition group, with an active charitable arm that dispenses social services nationwide, Nakhleh said it would not necessarily win a majority of votes in an open election. "They would be a hefty minority," he said, predicting that it would receive support from about 25 to 30 percent of the Egyptian population.